Mr Leithead, who is embedded with British troops, said an average of one of these vehicles a week was being lost and replacements sent from the UK often arrived late.

Lt Col Mayo said the WMIKs were taking "a hell of a hammering" in the hot and dusty conditions and said the situation was "tight, but not critical yet".

A fifth of the fleet is damaged or has been destroyed by enemy fire, he added, but more would be arriving soon.

Another vehicle, a Pinzgauer, has been fitted with extra armour to try to cover the shortfall, but there is a limit to the number of men and the amount of equipment they can carry, our correspondent said.

And the strain was increased because extra troops had recently been deployed without extra vehicles, he added.

A spokesman for the MoD denied there was a shortage and said huge investments had been made in equipment for the Army.

"The success of our forces against the Taleban shows that they are not only among the best in the world, but also among the best equipped," he said.